Existing physical vapor deposition (PVD) chambers typically utilize a two-piece shield configuration. The two-piece shield configuration comprises an upper shield, referred to as the dark space shield, and a lower shield, referred to as a ground shield. In the PVD chamber, particles sputtered from the target material, for example a dielectric material such as silicon, adhere to the dark space shield and the ground shield. However, the inventors have observed that silicon particles do not adhere well to the ground shield, and can peel off and contaminate the process chamber.
Accordingly, the inventors have provided improved apparatus for PVD processing.